20956660 has 12 divisors (see below), whose sum is σ = 44009028. Its totient is φ = 8382656.

The previous prime is 20956643. The next prime is 20956669. The reversal of 20956660 is 6665902.

It can be written as a sum of positive squares in 2 ways, for example, as 12418576 + 8538084 = 3524^2 + 2922^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20956669) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 523897 + ... + 523936.

It is an arithmetic number, because the mean of its divisors is an integer number (3667419).

Almost surely, 2^20956660 is an apocalyptic number.

20956660 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20956660 is an abundant number, since it is smaller than the sum of its proper divisors (23052368).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20956660 is a wasteful number, since it uses less digits than its factorization.

20956660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1047842 (or 1047840 counting only the distinct ones).

The product of its (nonzero) digits is 19440, while the sum is 34.

The square root of 20956660 is about 4577.8444709273. The cubic root of 20956660 is about 275.7024904539.

The spelling of 20956660 in words is "twenty million, nine hundred fifty-six thousand, six hundred sixty".